1. Field of the Invention
This invention relates to a sand belt device, more particularly to a sand belt device which can be mounted detachably on a body portion of a portable grinding machine in order to replace a grinding wheel that is attached originally to the body portion.
2. Description of the Related Art
Referring to FIG. 1, a portable grinding machine (G) has a body portion (1) which includes a handle part (1a) and a head part (1a'). The head part (1a') has a casing (1a"), a rotatable shaft (1b) which extends out from the casing (1a"), and an annular flange (1c) which protrudes from the casing (1a") and which is disposed around the rotatable shaft (1b). The portable grinding machine (G) further includes a grinding wheel (2) which is mounted detachably to the rotatable shaft (1b), and a housing (3) which covers the grinding wheel (2). The portable grinding machine (G) is used generally to remove a material from a workpiece with the grinding wheel (2). A polishing machine, which has an electrical driving mechanism and a sand belt mechanism, is necessary when polishing a surface of the workpiece. It is inconvenient and uneconomical to use a grinding machine and a polishing machine when grinding and polishing the workpiece.